604 research outputs found
Structure-activity relationships based on 3D-QSAR CoMFA/CoMSIA and design of aryloxypropanol-amine agonists with selectivity for the human β3-adrenergic receptor and anti-obesity and anti-diabetic profiles
Indexación: Scopus.Acknowledgments: This work was supported by FONDECYT No. 11130701. We would also like to thank fDoTr CthLeafbr efeora vthaeil afrbeilei tayvoafiltahbeilsitoyf towfa trheer seoqfutwireadret orecqaulciureladt etothcealAcuDla(thet ttph:e/ A/dDt c(lhatbt.pw:/e/dbstc.cloabm.w/seobfst.wcoamre/-stoofotlws aarned-tools and http://teqip.jdvu.ac.in/QSAR_Tools/). SDG. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest.The wide tissue distribution of the adrenergic β3 receptor makes it a potential target for the treatment of multiple pathologies such as diabetes, obesity, depression, overactive bladder (OAB), and cancer. Currently, there is only one drug on the market, mirabegron, approved for the treatment of OAB. In the present study, we have carried out an extensive structure-activity relationship analysis of a series of 41 aryloxypropanolamine compounds based on three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. This is the first combined comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) study in a series of selective aryloxypropanolamines displaying anti-diabetes and anti-obesity pharmacological profiles. The best CoMFA and CoMSIA models presented values of r2 ncv = 0.993 and 0.984 and values of r2 test = 0.865 and 0.918, respectively. The results obtained were subjected to extensive external validation (q2, r2, r2 m, etc.) and a final series of compounds was designed and their biological activity was predicted (best pEC50 = 8.561). © 2018 by the authors.https://www.mdpi.com/1420-3049/23/5/119
The Relationship between Visual-Spatial and Auditory-Verbal Working Memory Span in Senegalese and Ugandan Children
BACKGROUND: Using the Kaufman Assessment Battery for Children (K-ABC) Conant et al. (1999) observed that visual and auditory working memory (WM) span were independent in both younger and older children from DR Congo, but related in older American children and in Lao children. The present study evaluated whether visual and auditory WM span were independent in Ugandan and Senegalese children. METHOD: In a linear regression analysis we used visual (Spatial Memory, Hand Movements) and auditory (Number Recall) WM along with education and physical development (weight/height) as predictors. The predicted variable in this analysis was Word Order, which is a verbal memory task that has both visual and auditory memory components. RESULTS: Both the younger (<8.5 yrs) and older (>8.5 yrs) Ugandan children had auditory memory span (Number Recall) that was strongly predictive of Word Order performance. For both the younger and older groups of Senegalese children, only visual WM span (Spatial Memory) was strongly predictive of Word Order. Number Recall was not significantly predictive of Word Order in either age group. CONCLUSIONS: It is possible that greater literacy from more schooling for the Ugandan age groups mediated their greater degree of interdependence between auditory and verbal WM. Our findings support those of Conant et al., who observed in their cross-cultural comparisons that stronger education seemed to enhance the dominance of the phonological-auditory processing loop for WM
Evaluating the performance of model transformation styles in Maude
Rule-based programming has been shown to be very successful in many application areas. Two prominent examples are the specification of model transformations in model driven development approaches and the definition of structured operational semantics of formal languages. General rewriting frameworks such as Maude are flexible enough to allow the programmer to adopt and mix various rule styles. The choice between styles can be biased by the programmer’s background. For instance, experts in visual formalisms might prefer graph-rewriting styles, while experts in semantics might prefer structurally inductive rules. This paper evaluates the performance of different rule styles on a significant benchmark taken from the literature on model transformation. Depending on the actual transformation being carried out, our results show that different rule styles can offer drastically different performances. We point out the situations from which each rule style benefits to offer a valuable set of hints for choosing one style over the other
Synthesis and characterization of graphene/polythiophene (GR/PT) nanocomposites:Evaluation as high-performance supercapacitor electrodes
Composites of polythiophene (PT) and graphene (GR) with different mass proportions were studied for their application as supercapacitors. Fourier transform infrared spectroscopy (FTIR) along with High Resolution Scanning electron microscopy (HR-SEM) were employed in order to characterize the morphology and composition of the resulting composites. The electrochemical behaviour of these composites was studied by means of cyclic voltammetry and specific capacitance curves were derived from these measurements. The Faradaic impedance spectroscopy response of the different composites, along with that of GR, was also studied. From these measurements it was found that a 1:1 in mass composite of GR and PT showed a higher specific capacitance, even when compared with GR alone. The introduction of the GR in that proportion also showed an enhanced cyclic stability in comparison with the sole polymer. The high specific capacitance (365 F g-1 at 1 A g-1) of this composite material indicates its potential for use as an electrode material for supercapacitors.Fil: Melo, J. P.. Universidad Bernardo OHiggins; ChileFil: Schulz, Eduardo Nicolás. Universidad Nacional del Sur. Departamento de Ingeniería Química. Instituto de Ingeniería Electroquímica y Corrosión; Argentina. University of Birmingham; Reino UnidoFil: Morales Verdejo, C.. Universidad Bernardo OHiggins; ChileFil: Horswell, S. L.. University of Birmingham; Reino UnidoFil: Camarada, M. B.. Universidad Bernardo OHiggins; Chil
Investigating the Mechanisms of Hallucinogen-Induced Visions Using 3,4-Methylenedioxyamphetamine (MDA): A Randomized Controlled Trial in Humans
The mechanisms of drug-induced visions are poorly understood. Very few serotonergic hallucinogens have been studied in humans in decades, despite widespread use of these drugs and potential relevance of their mechanisms to hallucinations occurring in psychiatric and neurological disorders.We investigated the mechanisms of hallucinogen-induced visions by measuring the visual and perceptual effects of the hallucinogenic serotonin 5-HT2AR receptor agonist and monoamine releaser, 3,4-methylenedioxyamphetamine (MDA), in a double-blind placebo-controlled study. We found that MDA increased self-report measures of mystical-type experience and other hallucinogen-like effects, including reported visual alterations. MDA produced a significant increase in closed-eye visions (CEVs), with considerable individual variation. Magnitude of CEVs after MDA was associated with lower performance on measures of contour integration and object recognition.Drug-induced visions may have greater intensity in people with poor sensory or perceptual processing, suggesting common mechanisms with other hallucinatory syndromes. MDA is a potential tool to investigate mystical experiences and visual perception
Rewriting Logic Semantics of a Plan Execution Language
The Plan Execution Interchange Language (PLEXIL) is a synchronous language
developed by NASA to support autonomous spacecraft operations. In this paper,
we propose a rewriting logic semantics of PLEXIL in Maude, a high-performance
logical engine. The rewriting logic semantics is by itself a formal interpreter
of the language and can be used as a semantic benchmark for the implementation
of PLEXIL executives. The implementation in Maude has the additional benefit of
making available to PLEXIL designers and developers all the formal analysis and
verification tools provided by Maude. The formalization of the PLEXIL semantics
in rewriting logic poses an interesting challenge due to the synchronous nature
of the language and the prioritized rules defining its semantics. To overcome
this difficulty, we propose a general procedure for simulating synchronous set
relations in rewriting logic that is sound and, for deterministic relations,
complete. We also report on two issues at the design level of the original
PLEXIL semantics that were identified with the help of the executable
specification in Maude
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JOYCE: Jülich Observatory for cloud evolution
The Jülich Observatory for Cloud Evolution (JOYCE), located at Forschungszentrum Jülich in the most western part of Germany, is a recently established platform for cloud research. The main objective of JOYCE is to provide observations, which improve our understanding of the cloudy boundary layer in a midlatitude environment. Continuous and temporally highly resolved measurements that are specifically suited to characterize the diurnal cycle of water vapor, stability, and turbulence in the lower troposphere are performed with a special focus on atmosphere–surface interaction. In addition, instruments are set up to measure the micro- and macrophysical properties of clouds in detail and how they interact with different boundary layer processes and the large-scale synoptic situation. For this, JOYCE is equipped with an array of state-of-the-art active and passive remote sensing and in situ instruments, which are briefly described in this scientific overview. As an example, a 24-h time series of the evolution of a typical cumulus cloud-topped boundary layer is analyzed with respect to stability, turbulence, and cloud properties. Additionally, we present longer-term statistics, which can be used to elucidate the diurnal cycle of water vapor, drizzle formation through autoconversion, and warm versus cold rain precipitation formation. Both case studies and long-term observations are important for improving the representation of clouds in climate and numerical weather prediction models
Effects of ecstasy/polydrug use on memory for associative information
Rationale
Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination.
Objectives
A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users.
Methods
After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs.
Results
Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition.
Conclusions
Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value
Comments on Marine Litter in Oceans, Seas and Beaches: Characteristics and Impacts.
Marine litter is observed along shorelines, pelagic, benthic marine and lake
systems all around the globe. On beaches, litter creates aesthetic and related economic
problems because a clean beach is one of the most important characteristics of a
seaside resort required by visitors. Litter can reach the marine environment from marine
or land activities but it is estimated that 80% originates from land-based sources.
The marine-based sources of litter include all types of sea-going vessel and offshore
installations, the most abundant plastic debris in the oceans being derelict (lost or
improperly discarded) fishing gear. Most of marine litter is composed by plastics due
to their greater durability and persistence, combined with plastic rising production
and low rates of recovery. Special importance is linked to microplastics because
their ubiquity, persistence, mechanical effects on biota and the ecosystem because of
ingestion by organisms and their toxic potential. As plastics degrade they can release
toxic chemicals initially incorporated during their manufacturing or persistent organic
pollutants and heavy metals sorbed to their surfaces in the environment. Such toxins
can disrupt endocrine functions and cause harmful reproductive and developmental
effects in aquatic animals
Seasonality of Tylenchulus semipenetrans Cobb and Pasteuria sp in citrus orchards in Spain
Population densities of the Mediterranean biotype of Tylenchulus semipenetrans were monitored in soil and citrus roots at 3-month intervals for 3 consecutive years in four citrus orchards in the provinces of Tarragona (Amposta and Xalamera) and Valencia (Moncada and Carcer). Nematode population densities in soil peaked once year in April or July depending on the orchard and year. Numbers of females per gram of root increased once or twice each year. The maximum density of eggs per gram of root was recorded in April at Xalamera and Carcer orchards, but there was no recognizable peak in the other two orchards. Numbers of nematodes in soil, females or eggs program of root, of eggs per female were correlated with either temperature or rainfall in the sampling month, 1 month before sampling, or in the second preceding month, depending on the orchard. Members of the Pasteuria group were present in the four citrus orchards, and a positive relationship occurred between nematodes in soil and bacterial parasitism (r(2) = 0.75) in the orchard at Amposta
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